| 摘要 |
PURPOSE:To suppress the vibration of an AC motor by discriminating power drive or regenerative state from the polarity of a DC current, and correcting the basis frequency command of an inverter so as to cancel this state on the basis of the discrimination signal. CONSTITUTION:The input current ID of an inverter is detected by a current transformer 13, and the power drive or a regenerative state of an AC motor is discriminated from the polarity of a current by a current polarity discriminator 100. The basic frequency f1 of the inverter is corrected to become the power drive state if a regenerative mode is presented by a frequency correcting circuit 20, and the correction signal is output to an adder 300 to correct to become the regenerative state when the power drive mode is, on the contrary, presented, and added with a frequency set signal fR. |
